Perovskite nanocrystal fluorescent materials and preparation methods and applications thereof

Abstract

The present disclosure provides a perovskite nanocrystal fluorescent material comprising a micro-porous template and/or a mesoporous template, a substrate, and a perovskite nanocrystal. A substrate is attached to an inner surface of the micro-porous template and/or the mesoporous template and the perovskite nanocrystal is grown on a surface of the substrate. A melting point of the substrate is higher than a melting point of the perovskite nanocrystal. The perovskite nanocrystal fluorescent material has a high luminescence rate and high luminescence stability. The present disclosure also discloses a method for preparing the perovskite nanocrystal fluorescent material. The preparation method does not require organic solvents, and the preparation process is more green and environmentally friendly. The melt crystallization method adopted has a simple and controllable process, which is suitable for large-scale preparation of the perovskite nanocrystal. The present disclosure also discloses the application of the perovskite nanocrystal fluorescent material.

What is claimed is: 
     
         1 . A perovskite nanocrystal fluorescent material, comprising:
 at least one of a micro-porous template or a mesoporous template, and   a perovskite nanocrystal,   wherein
 a substrate is arranged on an inner surface of the at least one of the micro-porous template or the mesoporous template, 
 a lattice of the perovskite nanocrystal stacks with a lattice of the substrate to form a passivation interface, and 
 a melting point of the substrate is higher than a melting point of the perovskite nanocrystal. 
   
     
     
         2 . The perovskite nanocrystal fluorescent material according to  claim 1 , wherein the substrate includes one or more of metal oxide, metal fluoride, phosphate, and lead-tellurium-oxide halides. 
     
     
         3 . The perovskite nanocrystal fluorescent material according to  claim 2 , wherein
 the metal oxide is BaO, CaO, or Al 2 O 3 ,   the metal fluoride is CaF 2  or BaF 2 ,   the phosphate is Pb 3 (PO 4 ) 2  or AlPO 4 , and   the lead-tellurium-oxide halides is Pb 3 TeO 4 X 2 , wherein X is Br, I, or Cl.   
     
     
         4 . The perovskite nanocrystal fluorescent material according to  claim 1 , wherein the melting point of the substrate is higher than 570° C., and the melting point of the perovskite nanocrystal is not higher than 570° C. 
     
     
         5 . The perovskite nanocrystal fluorescent material according to  claim 1 , wherein the perovskite nanocrystal includes a cesium halide perovskite nanocrystal or a mixed halide perovskite nanocrystal. 
     
     
         6 . The perovskite nanocrystal fluorescent material according to  claim 5 , wherein the cesium halide perovskite nanocrystal has a perovskite structure ABX 3 , wherein A, B, and X have a molar ratio of 1:1:3, A is Cs, B is Pb, Sn, or Cu, and X is Cl, Br, or I. 
     
     
         7 . The perovskite nanocrystal fluorescent material according to  claim 5 , wherein the mixed halide perovskite nanocrystal has a perovskite structure ABX y X′ 3-y , wherein A, B, X, and X′ have a molar ratio of 1:1:y: 3 -y, y is between 0 and 3, A is Cs, B is Pb, Sn, or Cu, X and X′ are different and independently Cl, Br, or I. 
     
     
         8 . The perovskite nanocrystal fluorescent material according to  claim 1 , wherein
 the melting point of the substrate is higher than a failure temperature of the at least one of the micro-porous template or the mesoporous template, and   the failure temperature of the at least one of the micro-porous template or mesoporous template is higher than the melting point of the perovskite nanocrystal.   
     
     
         9 . The perovskite nanocrystal fluorescent material according to  claim 1 , wherein a mass ratio of the substrate to the perovskite nanocrystal is denoted as a, and a ranges between 0.02 and 10. 
     
     
         10 . The perovskite nanocrystal fluorescent material according to  claim 1 , wherein the at least one of the micro-porous template or the mesoporous template is made of at least one of a micro-porous material or a mesoporous material. 
     
     
         11 . The perovskite nanocrystal fluorescent material according to  claim 10 , wherein
 the micro-porous material is microporous molecular sieve, microporous silica, microporous titanium dioxide, microporous alumina, microporous transition metal oxide, microporous sulfide, microporous silicate, microporous aluminosilicates, or microporous transition metal nitride, and   the mesoporous material is mesoporous molecular sieve, mesoporous silica, mesoporous titanium dioxide, mesoporous alumina, mesoporous carbon, mesoporous transition metal oxide, mesoporous sulfide, mesoporous silicate, mesoporous aluminosilicate, or mesoporous transition metal nitride.   
     
     
         12 . A method for preparing a perovskite nanocrystal fluorescent material, wherein
 the perovskite nanocrystal fluorescent material comprises:
 at least one of a micro-porous template or a mesoporous template, and 
 a perovskite nanocrystal, 
 wherein
 a substrate is arranged on an inner surface of the at least one of the micro-porous template or the mesoporous template, 
 a lattice of the perovskite nanocrystal stacks with a lattice of the substrate to form a passivation interface, and 
 a melting point of the substrate is higher than a melting point of the perovskite nanocrystal, and 
 
   the method comprises the following steps:   (1) mixing a precursor of the perovskite nanocrystal, a precursor of the substrate, and the at least one of the micro-porous template or the mesoporous template to obtain a mixture; and   (2) under a temperature higher than the melting point of the perovskite nanocrystal and lower than a failure temperature of the at least one of the micro-porous template or the mesoporous template, performing calcination on the mixture obtained in step (1), and after cooling the mixture to a room temperature, obtaining the perovskite nanocrystal fluorescent material.   
     
     
         13 . The method according to  claim 12 , wherein the calcination in step (2) is composed of a heating-melting stage, an insulation-filling stage, and a cooling-growth stage in sequence;
 during the heating-melting stage, when a calcination temperature is higher than the melting point of the perovskite nanocrystal, the precursor of the perovskite nanocrystal and the precursor of the substrate form a molten liquid;   during the insulation-filling stage, when the calcination temperature is lower than the failure temperature of the at least one of the micro-porous template or the mesoporous template, the molten liquid fills a pore structure of the at least one of the micro-porous template or the mesoporous template;   during the cooling-growth stage, the substrate is formed inside the micro-porous template or the mesoporous template, and after the substrate is formed, the perovskite nanocrystal heterogeneously grows on a surface of the substrate, thus obtaining the perovskite nanocrystal fluorescent material.   
     
     
         14 . The method according to  claim 12 , wherein the precursor of the perovskite nanocrystal is a precursor of a cesium halide perovskite nanocrystal or a precursor of a mixed halide perovskite nanocrystal. 
     
     
         15 . The method according to  claim 14 , wherein the precursor of the cesium halide perovskite nanocrystal is a precursor of a perovskite structure ABX 3 , wherein A, B, and X have a molar ratio of 1:1:3, A is Cs, B is Pb, Sn, or Cu, and X is Cl, Br, or I; wherein
 a precursor of CsPbX 3  perovskite nanocrystal includes a Cs source precursor, a Pb source precursor, and an X source precursor;   a precursor of CsSnX 3  perovskite nanocrystal includes the Cs source precursor, a Sn source precursor, and the X source precursor; and   a precursor of CsCuX 3  perovskite nanocrystal includes the Cs source precursor, a Cu source precursor, and the X source precursor, wherein   the X source precursor is a halide source precursor.   
     
     
         16 . The method according to  claim 14 , wherein the precursor of the mixed halide perovskite nanocrystal is a precursor of a perovskite structure ABX y X′ 3-y , wherein A, B, X, and X′ have a molar ratio of 1:1:y: 3 -y, y is between 0 and 3, A is Cs, B is Pb, Sn, or Cu, X and X′ are different and independently Cl, Br, or I; wherein
 a precursor of CsPbX y X′ 3-y  perovskite nanocrystal includes a Cs source precursor, a Pb source precursor, an X source precursor, and an X′ source precursor; 
 a precursor of CsSnX y X′ 3-y  perovskite nanocrystal includes the Cs source precursor, a Sn source precursor, the X source precursor, and the X′ source precursor; and 
 a precursor of CsCuX y X′ 3-y  perovskite nanocrystal includes the Cs source precursor, a Cu source precursor, the X source precursor, and the X′ source precursor, wherein 
 the X source precursor and the X′ source precursor are different halide source precursors. 
 
     
     
         17 . The method according to  claim 16 , wherein
 the Cs source precursor is one or more of cesium halide and cesium carbonate;   the Pb source precursor is one or more of lead halide and lead acetate;   the Sn source precursor is tin halide;   the Cu source precursor is copper halide;   each halide source precursor is one or more of cesium halide, lead halide, zinc halide, potassium halide, sodium halide, lithium halide, ammonia halide, calcium halide, strontium halide, and barium halide.   
     
     
         18 . The method according to  claim 12 , wherein the precursor of the substrate is one or more of nitrate, nitrite, telluride, and hydrogen phosphate. 
     
     
         19 . The method according to  claim 18 , wherein
 the nitrate is Ce(NO 3 ) 3 ,   the nitrite is Ba(NO 2 ) 2  or Ca(NO 2 ) 2 ,   the telluride is TeO 2 , TeCl 4 , or TeBr 4 , and   the phosphate is Al(H 2 PO 4 ) 3 .   
     
     
         20 . The method according to  claim 12 , wherein the step (1) further includes:
 using a low melting point salt corresponding to any precursor of the precursor of the perovskite nanocrystal or the precursor of the substrate as a flux.